Sureboard



Aug. 8, 1944.

R. G` KIRCHNER 2,355,302

SURF BOARD Filed Nov. 18, 1940 :Slmcntor G ttorncgs Patented Aug. 8, 1944 ENT OFFICE `sUREBoARD. l

Richard GiKirchner, Sian Diego, Calif. Application November 1s,1940seria1N0-36a052 I Claims.

This 'invention relates: toaquatic amusement devices and in particular to surf boards.

Onefobj ect of `this invention is to provide'a. surf board having means associated therewith for increasing the driving effect of the Wave upon the I surf board.

Another object is to provide a surf board having a. step` on the bottom which catches the swirl of the crest oiga wave and increases the propulsive effect thereof. I Y

Another object is toprovide a surf, board asset forth in the preceding object whereinthe step'` is V shaped, so that` a tendency of the board to yaw or turn is counteracted by the pressure being increased on one side of the V step and lessened on the other side.

Another object is to provide a surf board having a plurality of steps on the bottom, these steps providing portions for the whirling crest of the wave to grip, thereby increasing the eiiiciency of the surf board by enhancing the propelling force thereon.

In the drawing:

Figure 1 is a top plan View of a surf board with a V-shaped step, according to one embodiment of the invention.

Figure 2 is a side elevation of the surf board shown in Figure 1.

Figure 3 is a top plan view of a modified form of surf board having a straight step.

Figure 4 is a top plan View of a modified form of surf board having a plurality of V-shaped steps.

Figure 5 is a side elevation of the surf board shown in Figure 4.

Figure 6 is a diagrammatic side elevation of the surf board of Figures 1 and 2 in use.

In general, the surf board of this invention consists of an elongated floating member, such as a wooden plank, having a step on the bottom thereof. The step is either V-shaped or extends straight across the surf board. A further modiiication contemplates the use of a plurality of steps on the bottom of the surf board. The step on the bottom of the surf board increases the propelling effect by giving an abutment which the whirling crest of the wave can grip. 'Ihe V-shaped step makes the surf board partially self-steering since any tendency of the board to yaw or turn is counteracted by the pressure being increased on one side of the V and decreased on the other side.

Referring to the drawing in detail, Figure 1 shows a surf board I!) having a pointed bow II, curved stern I2, and longitudinal sides I3. The surf board I0 is provided with an upper surface I4 and lower surfaces I54 and 'I6 on different levels and separatedA by a V-shaped step I'I having relatively angledvportions.I3` and I9. IAs shown inV Figure 2, the lower surfaces I5 and' I6 are sloped relativelyto one another so-that the surf board `is thicker at the step I1 than it isat the bow II `The Surfboard `2|), however, kis provided with a `straight stepf 2 I which extends acrosslthebottom of the surf board at right angles tothe sides 4I3 thereofinstead of the V-.shaped step II of Figure 1.

The modified form of surf board 30 shown in Figures 4 and 5 is generally similar to that shown in Figure 1 except that the bottomvsurfaces I5 and I 6 are separated by multiple V-shaped steps 3| and 32 having relatively angled walls 33, 34, 35 and 36 respectively. This surf board is thus similar to that of Figure 1, but with an additional step provided. v

In the operation of the surf board, the user swims out with the board or is towed out by boat to a point where large waves begin to roll in toward the shore. The swimmer then turns the surf board toward the shore, such as by paddling it around with his hands.

When the crest of a large wave comes beneath the surf board, this crest grips the step on the surf board as it whirls onward, propelling the surf board rapidly toward the shore. Thus the step catches the swirl at the top of a wave and enhances the driving power of the wave upon the i surf board.

The V-shaped step of Figures 1, 2, 4 and 5 makes the surf board at least partially self-steering, as compared with the surf board of Figure 3 with its straight step. The multiple or plural steps of the surf board of Figures 4 and 5 distribute the thrusting eiect of the wave between the two sets of shoulders provided by the two steps.

The sport of `surf riding cannot be practiced at every beach but is confined to beaches where the water is sufficiently shallow and the approach suiciently gradual so that large waves will be created and will roll rapidly toward theshore. The ordinary surf board with its comparatively smooth bottom is therefore capable of use only in a few limited locations. The surf board of the present invention, however, can be used at many beaches where the ordinary surf board would be comparatively useless since the step on the bottom of the present surf board is gripped by the whirling crest of the wave and thus the bottom is propelled rapidly, where without this step it Would be propelled too slowly or not at all.

While a specific embodiment of the invention has been described and illustrated, it will be understood that various modifications may be made within the scope of the appended claims Without departing from the spirit of the invention.

What I claim is: i K f 1. A wave propelled surf board comprising an elongated plank member relatively thin in proportion to its length and width and having in-,l

clined bottom walls converging from the front and rear of said board to the intermediate portion'V thereof and terminating at their inner ends onf different levels, obliquely-disposed vertical walls connecting said inclined bottom Walls at theirv point of termination to provide an intermediate V-shaped stepped shoulder lportion adapted to be engaged by the crest-of a Wave. i' v i 2. A Wave propelled surf board comprising an elongated plank member 'relatively thin in proportion to its length and width and having a flat plane upper surfacegand a plurality olf inclined bottom surfaces sloping relatively to one another toward the middle from relativelythin ends and terminating on different levels, said inclined bottomsurfaces being'connected by a vertical Wall' at their point of termination to provide a shoulder therebetween, and said shoulder being formed ataV location to be engaged by the crest of a wave. A A

`A wave propelled surf board comprising a lelongated plank member relatively thin in pro- 15- Vpor-tion to its length and width and having a plurality of similarly arranged horizontally V- shaped steps on the underside thereof, said V- shaped steps being adjacent one another and being approximately centrally positioned so as to be engaged by the crest of a Wave.

5. A Wave propelled surf board comprising an elongated plank member relatively thin in proportion to its length and width and having a plurality of bottom surfaces in diierent planes separated from one another by a step, said step having vertical walls extending obliquely from the edges ofthe board in a horizontally V-shaped Apath with the arms ofthe V converging toward a junction at the center thereof, said vertical Walls being positioned intermediate the ends of the board in a location, to be engaged by the crest of a wave.

' Y RICHARD G. KIRCHNER. 

